The sub-irrigation of plants growing in pots has received much attention in recent times as an inexpensive, non-labour intensive form of indoor plant maintenance.
Furthermore, the sub-irrigation of plants ensures that people unskilled in plant maintenance will not over water or under water the plants when watering from the top of the soil surface.
Most approaches to date have involved the removal of the plant with its surrounding intact soil structure from its growing pot and its transplantation into an impermeable decorative container that is adapted to house a sub-irrigation structure.
In one known method of this type, the decorative container has a tank located at its bottom and the plant with its soil structure is placed on top of the tank and backfilled with peat moss. The tank serves as a reservoir of water for the growing plant and has a filler tube through which water is fed into the tank and a structure referred to as a `capillary cone` which allows water from the tank to pass upwardly into the soil surrounding the roots of the plant. This system is, however, very expensive and is time consuming to install.
In another method, the decorative container has a water filled tank located at its bottom and a wick lying on the bottom of the growing pot with its ends passing into the tank through holes so that the wick ends are suspended in the water. Once again, the plant with its soil structure is knocked out of its growing pot and placed in the decorative container on top of the wick. Water passes along the wick by capillary attraction from within the tank and encounters the soil structure at its base.
Both the above mentioned methods require that the plant be removed from its growing pot into a decorative container. If the soil surrounding the roots of the plant does not remain intact during this transplantation, such as may occur with coarse soil or if an unskilled person haphazardly knocks the plant out from its growing pot, the future growth of the plant in the decorative container may be jeopardized.
Furthermore, the means for passing water to the soil in both methods only brings the water to the base of the soil structure and so the water still needs to be attracted up to near the roots of the plant before it can be absorbed.